| 摘要 |
An exhaust gas emission control device comprising a filter provided in the exhaust passage, a heater provided near the filter, first and second passage bypassing the filter and the heater, a single first valve upstream of the filter a single second valve downstream of the filter, and a controller controlling the first and the second valve. When trapping particles, one of or both of the first and second valves closes the first and second passages, and the first and second valves open the exhaust passage, whereby exhaust gas flows through the filter and the heater. On the other hand, when regenerating the filter, the heater is switched ON, the first valve shuts the exhaust passage and the second valve is open to a predetermined degree, so that exhaust gas flows into the first passage, and a part of the exhaust gas flowing via the first passage flows through the heater, the filter, and the second passage.
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